Matthias Urlichs reported that the dns_db_findrdataset() function fails
when the prerequisite section of the dynamic update message contains a
record of type "ANY" and where at least one RRset for this FQDN exists
on the server.

Impact

A remote unauthenticated attacker could send a specially crafted
dynamic update message to the BIND daemon (named), leading to a Denial
of Service (daemon crash). This vulnerability affects all primary
(master) servers -- it is not limited to those that are configured to
allow dynamic updates.